P2X1 receptors for ATP contribute to signalling in a variety of cell types and following stimulation undergo rapid desensitisation (within 1 s), and require approximately 5 min to recover. In HEK293 cells P2X1 receptors C-terminally tagged with enhanced green fluorescent protein (P2X1-eGFP) were predominantly expressed at the cell surface. Following > 90% photo-bleaching of P2X1-eGFP within a 6 microm(2) circle at the cell surface fluorescence recovery after photo-bleaching (FRAP) was fit with a time constant of approximately 60 s and recovered to approximately 75% of pre-bleach levels. Following activation of the P2X1 receptor with alpha,beta-methylene ATP the associated calcium influx doubled the FRAP recovery rate. The protein synthesis inhibitor cycloheximide had only a small effect on repeated FRAP and indicated a limited contribution of new P2X1 receptors to the FRAP. Inhibition of trafficking with brefeldin A reduced recovery and this effect could be reversed following receptor activation. In contrast, the dynamin inhibitor dynasore had no effect on FRAP under unstimulated conditions but reduced the level of recovery following agonist stimulation. In functional studies both brefeldin A and dynasore increased the recovery time from desensitisation. Taken together these studies demonstrate for the first time an important role of receptor recycling on P2X1 receptor responsiveness.
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http://dx.doi.org/10.1111/j.1471-4159.2010.06730.x | DOI Listing |
Toxicol In Vitro
December 2024
School of Animal Science and Technology, Foshan University, Foshan 528225, Guangdong Province, PR China. Electronic address:
Bongkrekic acid (BKA), a less well-known foodborne toxin, has been implicated in numerous poisoning incidents. Recent studies suggest that BKA exerts an impact on the immune system, particularly on innate immunity. The release of neutrophil extracellular traps (NETs) is relatively a newly-discovered mechanism involving innate immunity.
View Article and Find Full Text PDFNat Commun
October 2024
Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR, 97239, USA.
P2X receptors are a family of seven trimeric non-selective cation channels that are activated by extracellular ATP to play roles in the cardiovascular, neuronal, and immune systems. Although it is known that the P2X1 receptor subtype has increased sensitivity to ATP and fast desensitization kinetics, an underlying molecular explanation for these subtype-selective features is lacking. Here we report high-resolution cryo-EM structures of the human P2X1 receptor in the apo closed, ATP-bound desensitized, and the high-affinity antagonist NF449-bound inhibited states.
View Article and Find Full Text PDFNat Commun
September 2024
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.
The P2X1 receptor is a trimeric ligand-gated ion channel that plays an important role in urogenital and immune functions, offering the potential for new drug treatments. However, progress in this area has been hindered by limited structural information and a lack of well-characterised tool compounds. In this study, we employ cryogenic electron microscopy (cryo-EM) to elucidate the structures of the P2X1 receptor in an ATP-bound desensitised state and an NF449-bound closed state.
View Article and Find Full Text PDFHum Immunol
November 2024
Department of Medical Oncology, Ma'anshan People's Hospital, Ma'anshan, 243000, Anhui Province, China.
Background: The most abundant innate immune cells, neutrophils, contribute significantly to cancer development by stimulating immunosuppression. However, it remains unclear about its function and molecular mechanisms in the immunosuppressive microenvironment of non-small cell lung cancer (NSCLC).
Methods: Blood samples were collected from NSCLC patients and healthy volunteers to detect the expression of P2RX1 and PD-L1 in neutrophils using qRT-PCR, western blot (WB), and flow cytometry.
J Sex Med
October 2024
Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, County Louth A91 K584, Ireland.
Background: Evidence suggests that the corpus cavernosum smooth muscle (CCSM) cells of several species, including humans, express purinergic P2X receptors, but it is not known if the corpus cavernosum has an excitatory purinergic innervation.
Aim: In this study we aimed to determine if the mouse CCSM has a functional purinergic innervation.
Methods: Mouse CCSM myocytes were enzymatically isolated and studied using the perforated patch configuration of the patch clamp technique.
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